The present invention is in the area of hand-held striking tools, such as hammers, and pertains more specifically to the weights and swinging dynamics of such tools, accommodating a demand for a variety of weights for such tools, and improving claw hammer versatility.
Hand-held striking tools, such as claw hammers, have been used by people in a variety of disciplines for centuries as leveraged devices to provide a striking force to accomplish a seemingly endless variety of tasks. For example, a steel claw hammer, commonly weighing from 7 to 32 ounces is used by people doing carpentry work to deliver sufficient striking force to drive a nail into wood. A claw hammer is also used for removing a nail or ripping apart lumber using it""s claw. A sledge hammer, commonly weighing from 2 to 20 pounds, is used to deliver sufficient striking force for heavy work such as driving a stake, Rawl drill, chisel, or driving a wedge into masonry, stone, wood, or other hard materials.
Hand-held striking tools, such as those described above, are commonly used as third-class levers used to provide a striking force to accomplish tasks such as driving a nail into a piece of wood, bending or forming metal, breaking a rock, and other similar tasks. Third class levers are levers where a fulcrum, also referred to as a pivot point, is at one end of a bar or rod. A load to be overcome is an object creating resistance at the opposite end of a bar or rod. An effort, or force, to be applied to a third-class lever is somewhere in between a fulcrum and load. In the case of a hand-held striking tool such as a claw hammer, the fulcrum is a wrist. The force is provided by deceleration of the movement of a hammer handle (bar or rod) at the wrist, and the load is a resistance presented by a piece of wood into which the nail is being driven.
The head is at a distance from the fulcrum and moves faster than the movement being applied at a user""s hand, which is near the fulcrum. The increased speed of the head multiplies the applied force with which a striking device head strikes a nail or digs into the dirt. The longer a claw hammer""s handle, for example, the faster the head and the greater the force that strikes a nail and overcomes the resistance of the wood. This principle applies to all other hand-held striking devices, and is intensified in long-handled striking devices such as a pickaxe or an axe.
The load for a hand-held striking tool being used as a first class lever, such as in a claw hammer or a pickaxe, is typically very close to the fulcrum. Whereas the force for a hand-held striking tool being used as a third class lever is typically relatively far away from the fulcrum. During prying or pulling tasks, the load applied is therefore moved less distance than the hand, which is at the opposite end of the lever, and applying the force. This multiplies the force in which the claw hammer head pulls against a nail, or a pickaxe pulls against a rock.
As described above, hand-held striking devices typically come in a variety of weights, depending upon the task at hand or the physical condition of the user. For example, claw-hammers used for general carpenter work, commonly referred to as a curved-claw nail hammer, are typically manufactured and sold in weights from 7 to 20 ounces. Claw hammers designed and used for rough work such as framing, opening crates and prying apart boards, commonly referred to as ripping hammers, are typically manufactured and sold in weights from 20 to 32 ounces. The primary difference between a curved nail hammer and a ripping hammer is that the ripping hammer has a substantially straighter and longer claw than a curved nail claw.
Referring now to the fact of hammers of various weights, and the fact of the common and known materials used for hammer heads, there is a definite correlation between the size and general dimensions of a hammer head and the weight of the hammer head. The correlation causes some problems and narrows the scope of possibilities in dimension vs. weight for hammer heads.
What is clearly needed is a new material for hammer heads that is tough and strong, capable of hard surfaces, and lighter for size than hammers currently made.